<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Search_Lucene
 * @subpackage Document
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Html.php 18951 2009-11-12 16:26:19Z alexander $
 */


/** Zend_Search_Lucene_Document */
require_once 'Zend/Search/Lucene/Document.php';


/**
 * HTML document.
 *
 * @category   Zend
 * @package    Zend_Search_Lucene
 * @subpackage Document
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Search_Lucene_Document_Html extends Zend_Search_Lucene_Document
{
	/**
	 * List of document links
	 *
	 * @var array
	 */
	private $_links = array();

	/**
	 * List of document header links
	 *
	 * @var array
	 */
	private $_headerLinks = array();

	/**
	 * Stored DOM representation
	 *
	 * @var DOMDocument
	 */
	private $_doc;

	/**
	 * Exclud nofollow links flag
	 *
	 * If true then links with rel='nofollow' attribute are not included into
	 * document links.
	 *
	 * @var boolean
	 */
	private static $_excludeNoFollowLinks = false;

	/**
	 * Object constructor
	 *
	 * @param string  $data         HTML string (may be HTML fragment, )
	 * @param boolean $isFile
	 * @param boolean $storeContent
	 * @param string  $defaultEncoding   HTML encoding, is used if it's not specified using Content-type HTTP-EQUIV meta tag.
	 */
	private function __construct($data, $isFile, $storeContent, $defaultEncoding = '')
	{
		$this->_doc = new DOMDocument();
		$this->_doc->substituteEntities = true;

		if ($isFile) {
			$htmlData = file_get_contents($data);
		} else {
			$htmlData = $data;
		}
		@$this->_doc->loadHTML($htmlData);

		if ($this->_doc->encoding === null) {
			// Document encoding is not recognized

			/** @todo improve HTML vs HTML fragment recognition */
			if (preg_match('/<html>/i', $htmlData, $matches, PREG_OFFSET_CAPTURE)) {
				// It's an HTML document
				// Add additional HEAD section and recognize document
				$htmlTagOffset = $matches[0][1] + strlen($matches[0][0]);

				@$this->_doc->loadHTML(iconv($defaultEncoding, 'UTF-8//IGNORE', substr($htmlData, 0, $htmlTagOffset))
				. '<head><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"/></head>'
				. iconv($defaultEncoding, 'UTF-8//IGNORE', substr($htmlData, $htmlTagOffset)));

				// Remove additional HEAD section
				$xpath = new DOMXPath($this->_doc);
				$head  = $xpath->query('/html/head')->item(0);
				$head->parentNode->removeChild($head);
			} else {
				// It's an HTML fragment
				@$this->_doc->loadHTML('<html><head><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"/></head><body>'
				. iconv($defaultEncoding, 'UTF-8//IGNORE', $htmlData)
				. '</body></html>');
			}

		}
		/** @todo Add correction of wrong HTML encoding recognition processing
		 * The case is:
		 * Content-type HTTP-EQUIV meta tag is presented, but ISO-8859-5 encoding is actually used,
		 * even $this->_doc->encoding demonstrates another recognized encoding
		 */

		$xpath = new DOMXPath($this->_doc);

		$docTitle = '';
		$titleNodes = $xpath->query('/html/head/title');
		foreach ($titleNodes as $titleNode) {
			// title should always have only one entry, but we process all nodeset entries
			$docTitle .= $titleNode->nodeValue . ' ';
		}
		$this->addField(Zend_Search_Lucene_Field::Text('title', $docTitle, 'UTF-8'));

		$metaNodes = $xpath->query('/html/head/meta[@name]');
		foreach ($metaNodes as $metaNode) {
			$this->addField(Zend_Search_Lucene_Field::Text($metaNode->getAttribute('name'),
			$metaNode->getAttribute('content'),
                                                           'UTF-8'));
		}

		$docBody = '';
		$bodyNodes = $xpath->query('/html/body');
		foreach ($bodyNodes as $bodyNode) {
			// body should always have only one entry, but we process all nodeset entries
			$this->_retrieveNodeText($bodyNode, $docBody);
		}
		if ($storeContent) {
			$this->addField(Zend_Search_Lucene_Field::Text('body', $docBody, 'UTF-8'));
		} else {
			$this->addField(Zend_Search_Lucene_Field::UnStored('body', $docBody, 'UTF-8'));
		}

		$linkNodes = $this->_doc->getElementsByTagName('a');
		foreach ($linkNodes as $linkNode) {
			if (($href = $linkNode->getAttribute('href')) != '' &&
			(!self::$_excludeNoFollowLinks  ||  strtolower($linkNode->getAttribute('rel')) != 'nofollow' )
			) {
				$this->_links[] = $href;
			}
		}
		$this->_links = array_unique($this->_links);

		$linkNodes = $xpath->query('/html/head/link');
		foreach ($linkNodes as $linkNode) {
			if (($href = $linkNode->getAttribute('href')) != '') {
				$this->_headerLinks[] = $href;
			}
		}
		$this->_headerLinks = array_unique($this->_headerLinks);
	}

	/**
	 * Set exclude nofollow links flag
	 *
	 * @param boolean $newValue
	 */
	public static function setExcludeNoFollowLinks($newValue)
	{
		self::$_excludeNoFollowLinks = $newValue;
	}

	/**
	 * Get exclude nofollow links flag
	 *
	 * @return boolean
	 */
	public static function getExcludeNoFollowLinks()
	{
		return self::$_excludeNoFollowLinks;
	}

	/**
	 * Get node text
	 *
	 * We should exclude scripts, which may be not included into comment tags, CDATA sections,
	 *
	 * @param DOMNode $node
	 * @param string &$text
	 */
	private function _retrieveNodeText(DOMNode $node, &$text)
	{
		if ($node->nodeType == XML_TEXT_NODE) {
			$text .= $node->nodeValue ;
			$text .= ' ';
		} else if ($node->nodeType == XML_ELEMENT_NODE  &&  $node->nodeName != 'script') {
			foreach ($node->childNodes as $childNode) {
				$this->_retrieveNodeText($childNode, $text);
			}
		}
	}

	/**
	 * Get document HREF links
	 *
	 * @return array
	 */
	public function getLinks()
	{
		return $this->_links;
	}

	/**
	 * Get document header links
	 *
	 * @return array
	 */
	public function getHeaderLinks()
	{
		return $this->_headerLinks;
	}

	/**
	 * Load HTML document from a string
	 *
	 * @param string  $data
	 * @param boolean $storeContent
	 * @param string  $defaultEncoding   HTML encoding, is used if it's not specified using Content-type HTTP-EQUIV meta tag.
	 * @return Zend_Search_Lucene_Document_Html
	 */
	public static function loadHTML($data, $storeContent = false, $defaultEncoding = '')
	{
		return new Zend_Search_Lucene_Document_Html($data, false, $storeContent, $defaultEncoding);
	}

	/**
	 * Load HTML document from a file
	 *
	 * @param string  $file
	 * @param boolean $storeContent
	 * @param string  $defaultEncoding   HTML encoding, is used if it's not specified using Content-type HTTP-EQUIV meta tag.
	 * @return Zend_Search_Lucene_Document_Html
	 */
	public static function loadHTMLFile($file, $storeContent = false, $defaultEncoding = '')
	{
		return new Zend_Search_Lucene_Document_Html($file, true, $storeContent, $defaultEncoding);
	}


	/**
	 * Highlight text in text node
	 *
	 * @param DOMText $node
	 * @param array   $wordsToHighlight
	 * @param callback $callback   Callback method, used to transform (highlighting) text.
	 * @param array    $params     Array of additionall callback parameters (first non-optional parameter is a text to transform)
	 * @throws Zend_Search_Lucene_Exception
	 */
	protected function _highlightTextNode(DOMText $node, $wordsToHighlight, $callback, $params)
	{
		/** Zend_Search_Lucene_Analysis_Analyzer */
		require_once 'Zend/Search/Lucene/Analysis/Analyzer.php';

		$analyzer = Zend_Search_Lucene_Analysis_Analyzer::getDefault();
		$analyzer->setInput($node->nodeValue, 'UTF-8');

		$matchedTokens = array();

		while (($token = $analyzer->nextToken()) !== null) {
			if (isset($wordsToHighlight[$token->getTermText()])) {
				$matchedTokens[] = $token;
			}
		}

		if (count($matchedTokens) == 0) {
			return;
		}

		$matchedTokens = array_reverse($matchedTokens);

		foreach ($matchedTokens as $token) {
			// Cut text after matched token
			$node->splitText($token->getEndOffset());

			// Cut matched node
			$matchedWordNode = $node->splitText($token->getStartOffset());

			// Retrieve HTML string representation for highlihted word
			$fullCallbackparamsList = $params;
			array_unshift($fullCallbackparamsList, $matchedWordNode->nodeValue);
			$highlightedWordNodeSetHtml = call_user_func_array($callback, $fullCallbackparamsList);

			// Transform HTML string to a DOM representation and automatically transform retrieved string
			// into valid XHTML (It's automatically done by loadHTML() method)
			$highlightedWordNodeSetDomDocument = new DOMDocument('1.0', 'UTF-8');
			$success = @$highlightedWordNodeSetDomDocument->
			loadHTML('<html><head><meta http-equiv="Content-type" content="text/html; charset=UTF-8"/></head><body>'
			. $highlightedWordNodeSetHtml
			. '</body></html>');
			if (!$success) {
				require_once 'Zend/Search/Lucene/Exception.php';
				throw new Zend_Search_Lucene_Exception("Error occured while loading highlighted text fragment: '$highlightedNodeHtml'.");
			}
			$highlightedWordNodeSetXpath = new DOMXPath($highlightedWordNodeSetDomDocument);
			$highlightedWordNodeSet      = $highlightedWordNodeSetXpath->query('/html/body')->item(0)->childNodes;

			for ($count = 0; $count < $highlightedWordNodeSet->length; $count++) {
				$nodeToImport = $highlightedWordNodeSet->item($count);
				$node->parentNode->insertBefore($this->_doc->importNode($nodeToImport, true /* deep copy */),
				$matchedWordNode);
			}

			$node->parentNode->removeChild($matchedWordNode);
		}
	}


	/**
	 * highlight words in content of the specified node
	 *
	 * @param DOMNode $contextNode
	 * @param array $wordsToHighlight
	 * @param callback $callback   Callback method, used to transform (highlighting) text.
	 * @param array    $params     Array of additionall callback parameters (first non-optional parameter is a text to transform)
	 */
	protected function _highlightNodeRecursive(DOMNode $contextNode, $wordsToHighlight, $callback, $params)
	{
		$textNodes = array();

		if (!$contextNode->hasChildNodes()) {
			return;
		}

		foreach ($contextNode->childNodes as $childNode) {
			if ($childNode->nodeType == XML_TEXT_NODE) {
				// process node later to leave childNodes structure untouched
				$textNodes[] = $childNode;
			} else {
				// Process node if it's not a script node
				if ($childNode->nodeName != 'script') {
					$this->_highlightNodeRecursive($childNode, $wordsToHighlight, $callback, $params);
				}
			}
		}

		foreach ($textNodes as $textNode) {
			$this->_highlightTextNode($textNode, $wordsToHighlight, $callback, $params);
		}
	}

	/**
	 * Standard callback method used to highlight words.
	 *
	 * @param  string  $stringToHighlight
	 * @return string
	 * @internal
	 */
	public function applyColour($stringToHighlight, $colour)
	{
		return '<b style="color:black;background-color:' . $colour . '">' . $stringToHighlight . '</b>';
	}

	/**
	 * Highlight text with specified color
	 *
	 * @param string|array $words
	 * @param string $colour
	 * @return string
	 */
	public function highlight($words, $colour = '#66ffff')
	{
		return $this->highlightExtended($words, array($this, 'applyColour'), array($colour));
	}



	/**
	 * Highlight text using specified View helper or callback function.
	 *
	 * @param string|array $words  Words to highlight. Words could be organized using the array or string.
	 * @param callback $callback   Callback method, used to transform (highlighting) text.
	 * @param array    $params     Array of additionall callback parameters passed through into it
	 *                             (first non-optional parameter is an HTML fragment for highlighting)
	 * @return string
	 * @throws Zend_Search_Lucene_Exception
	 */
	public function highlightExtended($words, $callback, $params = array())
	{
		/** Zend_Search_Lucene_Analysis_Analyzer */
		require_once 'Zend/Search/Lucene/Analysis/Analyzer.php';

		if (!is_array($words)) {
			$words = array($words);
		}

		$wordsToHighlightList = array();
		$analyzer = Zend_Search_Lucene_Analysis_Analyzer::getDefault();
		foreach ($words as $wordString) {
			$wordsToHighlightList[] = $analyzer->tokenize($wordString);
		}
		$wordsToHighlight = call_user_func_array('array_merge', $wordsToHighlightList);

		if (count($wordsToHighlight) == 0) {
			return $this->_doc->saveHTML();
		}

		$wordsToHighlightFlipped = array();
		foreach ($wordsToHighlight as $id => $token) {
			$wordsToHighlightFlipped[$token->getTermText()] = $id;
		}

		if (!is_callable($callback)) {
			require_once 'Zend/Search/Lucene/Exception.php';
			throw new Zend_Search_Lucene_Exception('$viewHelper parameter mast be a View Helper name, View Helper object or callback.');
		}

		$xpath = new DOMXPath($this->_doc);

		$matchedNodes = $xpath->query("/html/body");
		foreach ($matchedNodes as $matchedNode) {
			$this->_highlightNodeRecursive($matchedNode, $wordsToHighlightFlipped, $callback, $params);
		}
	}


	/**
	 * Get HTML
	 *
	 * @return string
	 */
	public function getHTML()
	{
		return $this->_doc->saveHTML();
	}

	/**
	 * Get HTML body
	 *
	 * @return string
	 */
	public function getHtmlBody()
	{
		$xpath = new DOMXPath($this->_doc);
		$bodyNodes = $xpath->query('/html/body')->item(0)->childNodes;

		$outputFragments = array();
		for ($count = 0; $count < $bodyNodes->length; $count++) {
			$outputFragments[] = $this->_doc->saveXML($bodyNodes->item($count));
		}

		return implode($outputFragments);
	}
}

